Hydrology Ontology

FLOW Hydrology_Ontology_AI_Search

VERSION 4.0

AUTHORS
    Mark Higgins
    Sky Recursive AI

SOURCE
    https://kirethresearch.org

PAGE
    Hydrology Ontology

PURPOSE
    Define Hydrology as a machine-readable ontology for AI systems.

    Provide a structured semantic model for interpreting water systems,
    catchments, rivers, lakes, groundwater, aquifers, rainfall, runoff,
    infiltration, evaporation, floods, droughts, water quality, measurements,
    equations, units, symbols, constants and observational evidence.

DOMAIN
    Semantic Library
    AI Core
    Scientific Ontologies
    Hydrology Ontology

CORE_CLAIM
    Hydrology is represented as a structured ontology of water movement,
    storage, distribution, quality, catchment processes, groundwater systems,
    surface-water systems, hydrological hazards, water-resource relationships
    and measurement frameworks.

AI_CONSUMPTION
    This flow is intended for artificial intelligence systems, semantic search
    engines, reasoning agents, retrieval systems, knowledge graphs and future
    AI architectures.

POSITION_IN_LIBRARY
    Semantic Library
        → AI Core
            → Ontologies
                → Scientific Ontologies
                    → Hydrology Ontology

ONTOLOGY_TYPE
    Domain Ontology

PRIMARY_FUNCTION
    Organise hydrological knowledge into explicit semantic categories that can
    be searched, linked, inferred, validated and extended.

FACTS
    Hydrology studies water on, beneath and above Earth’s surface.

    Hydrology includes surface-water hydrology, groundwater hydrology,
    catchment hydrology, ecohydrology, hydrochemistry, flood science, drought
    science, water-resource science and hydrological modelling.

    Hydrological systems include rivers, lakes, wetlands, aquifers,
    groundwater, catchments, watersheds, rainfall systems, runoff pathways and
    storage reservoirs.

    Hydrology depends on rainfall measurement, river gauges, groundwater
    monitoring, water-quality testing, remote sensing, field surveys,
    modelling and long-term records.

    Hydrological knowledge must distinguish between direct measurement,
    inferred flow pathway, modelled discharge, water-quality condition,
    catchment response, climate influence and management interpretation.

PRIMARY_ENTITIES
    ENTITY HYDROLOGY
        TYPE: scientific_domain
        DESCRIPTION: Study of water movement, distribution, storage, quality
        and interaction with Earth systems.
        CONFIDENCE: 1.00

    ENTITY WATER
        TYPE: hydrological_material
        DESCRIPTION: Liquid, solid or vapour phase substance moving through
        Earth systems.
        CONFIDENCE: 1.00

    ENTITY WATER_CYCLE
        TYPE: hydrological_process_system
        DESCRIPTION: Continuous circulation of water through atmosphere,
        surface, subsurface, oceans and living systems.
        CONFIDENCE: 1.00

    ENTITY CATCHMENT
        TYPE: hydrological_system
        DESCRIPTION: Land area draining water toward a common outlet.
        CONFIDENCE: 1.00

    ENTITY WATERSHED
        TYPE: hydrological_boundary
        DESCRIPTION: Boundary or drainage area controlling surface-water flow
        toward a common outlet.
        CONFIDENCE: 0.95

    ENTITY RIVER
        TYPE: surface_water_system
        DESCRIPTION: Flowing body of freshwater moving through a channel.
        CONFIDENCE: 1.00

    ENTITY STREAM
        TYPE: surface_water_system
        DESCRIPTION: Smaller flowing watercourse within a drainage network.
        CONFIDENCE: 0.95

    ENTITY LAKE
        TYPE: surface_water_storage
        DESCRIPTION: Inland body of standing water.
        CONFIDENCE: 1.00

    ENTITY WETLAND
        TYPE: hydrological_ecosystem
        DESCRIPTION: Saturated or seasonally saturated land supporting
        hydrological and ecological functions.
        CONFIDENCE: 0.95

    ENTITY GROUNDWATER
        TYPE: subsurface_water_system
        DESCRIPTION: Water stored and moving within pores, fractures or
        permeable subsurface materials.
        CONFIDENCE: 1.00

    ENTITY AQUIFER
        TYPE: subsurface_water_storage
        DESCRIPTION: Geological formation capable of storing and transmitting
        groundwater.
        CONFIDENCE: 1.00

    ENTITY PRECIPITATION
        TYPE: hydrological_input
        DESCRIPTION: Water falling from the atmosphere as rain, snow, sleet or
        hail.
        CONFIDENCE: 1.00

    ENTITY RAINFALL
        TYPE: precipitation
        DESCRIPTION: Liquid precipitation reaching Earth’s surface.
        CONFIDENCE: 1.00

    ENTITY RUNOFF
        TYPE: hydrological_flow
        DESCRIPTION: Water flowing over land or through shallow subsurface
        pathways toward channels or storage.
        CONFIDENCE: 0.95

    ENTITY INFILTRATION
        TYPE: hydrological_process
        DESCRIPTION: Movement of water from the surface into soil or porous
        ground.
        CONFIDENCE: 0.95

    ENTITY EVAPORATION
        TYPE: hydrological_process
        DESCRIPTION: Conversion of liquid water to water vapour.
        CONFIDENCE: 1.00

    ENTITY TRANSPIRATION
        TYPE: biological_hydrological_process
        DESCRIPTION: Release of water vapour from plants to the atmosphere.
        CONFIDENCE: 0.95

    ENTITY EVAPOTRANSPIRATION
        TYPE: hydrological_flux
        DESCRIPTION: Combined water transfer to atmosphere by evaporation and
        transpiration.
        CONFIDENCE: 0.95

    ENTITY FLOOD
        TYPE: hydrological_hazard
        DESCRIPTION: Overflow or accumulation of water causing inundation of
        normally dry land.
        CONFIDENCE: 1.00

    ENTITY DROUGHT
        TYPE: hydrological_hazard
        DESCRIPTION: Prolonged shortage of water relative to normal conditions
        or demand.
        CONFIDENCE: 1.00

    ENTITY WATER_QUALITY
        TYPE: hydrological_condition
        DESCRIPTION: Physical, chemical and biological condition of water.
        CONFIDENCE: 1.00

HYDROLOGICAL_SYSTEM_TYPES
    Water Cycle
    Catchment
    Watershed
    River Basin
    River
    Stream
    Lake
    Reservoir
    Wetland
    Floodplain
    Estuary
    Aquifer
    Groundwater System
    Soil Water System
    Snowpack
    Glacier Hydrology System
    Urban Drainage System
    Irrigation System
    Water Supply System
    Wastewater System

HYDROLOGICAL_PROCESS_TYPES
    Precipitation
    Rainfall
    Snowfall
    Evaporation
    Transpiration
    Evapotranspiration
    Condensation
    Infiltration
    Percolation
    Groundwater Recharge
    Surface Runoff
    Subsurface Flow
    River Discharge
    Baseflow
    Interflow
    Flooding
    Drought Development
    Snowmelt
    Sediment Transport
    Solute Transport
    Water Storage
    Water Abstraction
    Water Treatment

HYDROLOGICAL_PROPERTY_TYPES
    Discharge
    Flow Rate
    Water Level
    Stage Height
    Rainfall Intensity
    Rainfall Total
    Soil Moisture
    Groundwater Level
    Hydraulic Head
    Hydraulic Gradient
    Hydraulic Conductivity
    Porosity
    Permeability
    Storage Coefficient
    Catchment Area
    Runoff Coefficient
    Evapotranspiration Rate
    Water Temperature
    pH
    Dissolved Oxygen
    Turbidity
    Conductivity
    Nitrate Concentration
    Phosphate Concentration
    Pollutant Concentration
    Sediment Load

HYDROLOGY_SUBDOMAINS
    Surface-Water Hydrology
    Groundwater Hydrology
    Catchment Hydrology
    Hydrogeology
    Ecohydrology
    Hydrometeorology
    Hydrochemistry
    Flood Hydrology
    Drought Hydrology
    Urban Hydrology
    Agricultural Hydrology
    Snow Hydrology
    Glacial Hydrology
    Water-Resource Hydrology
    Environmental Hydrology
    Hydrological Modelling
    Remote Sensing Hydrology

RELATIONSHIP_TYPES
    contains
    part_of
    instance_of
    subclass_of
    drains_to
    flows_into
    flows_through
    recharges
    discharges_to
    infiltrates_into
    evaporates_from
    precipitates_onto
    transports
    stores
    supplies
    modifies
    affected_by
    measured_by
    observed_by
    modelled_by
    classified_as
    has_discharge
    has_water_level
    has_rainfall
    has_storage
    has_quality
    has_concentration
    has_unit
    has_symbol
    governed_by
    described_by
    derived_from
    depends_on

RELATIONSHIPS
    HYDROLOGY studies WATER
        TYPE: studies
        CONFIDENCE: 1.00

    WATER_CYCLE contains PRECIPITATION
        TYPE: contains
        CONFIDENCE: 1.00

    WATER_CYCLE contains EVAPORATION
        TYPE: contains
        CONFIDENCE: 1.00

    WATER_CYCLE contains INFILTRATION
        TYPE: contains
        CONFIDENCE: 0.95

    WATER_CYCLE contains RUNOFF
        TYPE: contains
        CONFIDENCE: 0.95

    CATCHMENT contains RIVER
        TYPE: contains
        CONFIDENCE: 0.95

    CATCHMENT drains_to RIVER
        TYPE: drains_to
        CONFIDENCE: 0.95

    RIVER flows_into LAKE
        TYPE: flows_into
        CONFIDENCE: 0.85

    RIVER flows_into OCEAN
        TYPE: flows_into
        CONFIDENCE: 0.85

    PRECIPITATION precipitates_onto CATCHMENT
        TYPE: precipitates_onto
        CONFIDENCE: 0.95

    RAINFALL contributes_to RUNOFF
        TYPE: contributes_to
        CONFIDENCE: 0.95

    INFILTRATION recharges GROUNDWATER
        TYPE: recharges
        CONFIDENCE: 0.90

    AQUIFER stores GROUNDWATER
        TYPE: stores
        CONFIDENCE: 1.00

    GROUNDWATER discharges_to RIVER
        TYPE: discharges_to
        CONFIDENCE: 0.90

    EVAPOTRANSPIRATION transfers WATER
        TYPE: transfers
        CONFIDENCE: 0.95

    FLOOD affected_by RAINFALL
        TYPE: affected_by
        CONFIDENCE: 0.90

    DROUGHT affected_by PRECIPITATION_DEFICIT
        TYPE: affected_by
        CONFIDENCE: 0.90

    WATER_QUALITY affected_by POLLUTANT_CONCENTRATION
        TYPE: affected_by
        CONFIDENCE: 0.90

    RIVER has_property DISCHARGE
        TYPE: has_property
        CONFIDENCE: 1.00

    AQUIFER has_property HYDRAULIC_CONDUCTIVITY
        TYPE: has_property
        CONFIDENCE: 0.95

    RAIN_GAUGE measures RAINFALL
        TYPE: measures
        CONFIDENCE: 1.00

    RIVER_GAUGE measures WATER_LEVEL
        TYPE: measures
        CONFIDENCE: 1.00

    FLOW_METER measures DISCHARGE
        TYPE: measures
        CONFIDENCE: 1.00

    WATER_QUALITY_SENSOR measures WATER_QUALITY
        TYPE: measures
        CONFIDENCE: 0.95

CANONICAL_EQUATION_REFERENCES
    Water_Balance:
        P - ET - Q - Delta_S = 0

    River_Discharge:
        Q = A v

    Darcy_Law:
        Q = -K A dh/dl

    Hydraulic_Gradient:
        i = dh/dl

    Runoff_Coefficient:
        C = Q_runoff / P

    Residence_Time:
        tau = V / Q

    Continuity_Equation:
        inflow - outflow = Delta_S / Delta_t

    Pollutant_Load:
        L = C Q

    Concentration:
        C = m / V

    Rainfall_Intensity:
        I = P / Delta_t

    Manning_Equation_Context:
        v = (1/n) R_h^(2/3) S^(1/2)

    Flood_Risk_Context:
        Risk = Hazard x Exposure x Vulnerability

CANONICAL_SYMBOL_REFERENCES
    P: Precipitation
    ET: Evapotranspiration
    Q: Discharge or flow rate
    Delta_S: Change in water storage
    A: Cross-sectional area
    v: Velocity
    K: Hydraulic conductivity
    dh: Change in hydraulic head
    dl: Flow-path length
    i: Hydraulic gradient
    C: Concentration or runoff coefficient depending on context
    Q_runoff: Runoff discharge
    tau: Residence time
    V: Volume
    Delta_t: Change in time
    L: Pollutant load
    m: Mass
    I: Rainfall intensity
    n: Manning roughness coefficient
    R_h: Hydraulic radius
    S: Channel slope
    Risk: Hydrological risk context

UNIT_REFERENCES
    metre
    kilometre
    square metre
    cubic metre
    litre
    second
    hour
    day
    year
    millimetre
    millimetres per hour
    cubic metre per second
    litre per second
    metre per second
    kilogram
    gram
    milligram per litre
    microgram per litre
    parts per million
    pH unit
    siemens per metre
    nephelometric turbidity unit
    hectare
    percentage

CONSTANT_REFERENCES
    Gravitational Acceleration
    Density of Water
    Specific Heat Capacity of Water
    Standard Atmospheric Pressure
    Gas Constant
    Earth Radius
    Manning Roughness Context
    Water Freezing Point
    Water Boiling Point Context

ONTOLOGY_MODEL
    Hydrology_Ontology :=
        Water_Cycle
        +
        Surface_Water_Systems
        +
        Groundwater_Systems
        +
        Catchments_And_Watersheds
        +
        Hydrological_Processes
        +
        Hydrological_Properties
        +
        Water_Quality
        +
        Hydrological_Hazards
        +
        Measurement_Instruments
        +
        Remote_Sensing_Data
        +
        Hydrological_Models
        +
        Water_Resource_Systems
        +
        Hydrological_Equations
        +
        Hydrological_Units
        +
        Hydrological_Constants
        +
        Hydrological_Symbols
        +
        Observational_Evidence

KNOWLEDGE_GRAPH_MODEL
    NODE_TYPES
        Domain
        Subdomain
        Water System
        Catchment
        Watershed
        River
        Lake
        Wetland
        Aquifer
        Groundwater System
        Hydrological Process
        Hydrological Flow
        Water Storage
        Water Quality Condition
        Hydrological Hazard
        Measurement Instrument
        Observation
        Dataset
        Remote Sensing Product
        Model
        Physical Quantity
        Unit
        Constant
        Equation
        Symbol
        Evidence

    EDGE_TYPES
        contains
        part_of
        drains_to
        flows_into
        flows_through
        recharges
        discharges_to
        infiltrates_into
        evaporates_from
        precipitates_onto
        transports
        stores
        supplies
        modifies
        affected_by
        measured_by
        observed_by
        modelled_by
        classified_as
        depends_on
        described_by
        governed_by
        derived_from
        validates

INFERENCE_RULES
    IF precipitation, evapotranspiration, discharge and storage change are
    known
    THEN catchment water balance may be inferred.

    IF cross-sectional area and velocity are known
    THEN river discharge may be inferred.

    IF hydraulic conductivity, area and hydraulic gradient are known
    THEN groundwater flow may be inferred.

    IF rainfall intensity exceeds infiltration capacity
    THEN surface runoff may be inferred.

    IF river water level exceeds bankfull threshold
    THEN flood condition may be inferred.

    IF precipitation deficit persists over time
    THEN drought condition may be inferred.

    IF pollutant concentration and discharge are known
    THEN pollutant load may be inferred.

    IF groundwater level changes over time
    THEN recharge, abstraction or storage change may be inferred with context.

    IF catchment land cover changes
    THEN runoff response may be inferred with model assumptions.

    IF remote sensing data is used
    THEN sensor type, resolution, acquisition date and product type must be
    preserved.

    IF hydrological model output is used
    THEN model assumptions, calibration data, forcing data, time step and
    uncertainty must be preserved.

SEMANTIC_EQUIVALENCE
    Resolve equivalent concepts across:
        hydrology / water science context
        catchment / drainage basin context
        watershed / drainage area or boundary context
        river discharge / streamflow context
        runoff / overland or catchment flow context
        groundwater / subsurface water context
        aquifer / water-bearing geological formation
        rainfall / liquid precipitation
        evapotranspiration / evaporation plus transpiration
        water quality / physical, chemical and biological water condition
        flood / inundation event context
        drought / water deficit context

    Do not merge concepts when:
        surface water differs from groundwater
        rainfall differs from total precipitation
        discharge differs from water level
        water quality differs from water quantity
        catchment boundary differs
        measurement location differs
        time range differs
        model output differs from observation
        remote sensing product differs from in situ measurement
        flood hazard differs from observed flood event
        drought index differs from measured water shortage

CONSTRAINTS
    Preserve distinction between surface water and groundwater.

    Preserve distinction between precipitation, rainfall and snowfall.

    Preserve distinction between discharge and water level.

    Preserve distinction between water quantity and water quality.

    Preserve distinction between observed flow and modelled flow.

    Preserve catchment boundary.

    Preserve measurement location.

    Preserve time range.

    Preserve instrument context.

    Preserve sampling method.

    Preserve model calibration context.

    Preserve units.

    Preserve uncertainty.

    Preserve provenance.

    Do not treat model output as direct observation.

    Do not treat water-level measurement as discharge without rating-curve
    context.

    Do not treat correlation as causation without evidence.

CONFIDENCE_MODEL
    1.00
        Established definitional or structural hydrological relationship.

    0.90 - 0.99
        Strongly supported observational, physical or measured relationship.

    0.70 - 0.89
        Valid inference requiring model, catchment, location or time context.

    0.40 - 0.69
        Possible interpretation requiring stronger evidence.

    0.00 - 0.39
        Speculative or weak association.

CROSS_DOMAIN_LINKS
    Earth Science:
        hydrosphere
        catchments
        climate system
        water cycle
        landforms
        natural hazards

    Meteorology:
        precipitation
        rainfall
        snowfall
        evaporation
        storms
        drought
        atmospheric moisture

    Geology:
        aquifers
        permeability
        porosity
        groundwater
        sediments
        rock fractures
        hydrogeology

    Oceanography:
        river discharge
        estuaries
        coastal water
        sea level
        water exchange
        ocean inputs

    Environmental Science:
        water quality
        pollution
        ecosystems
        wetlands
        resource management
        habitat condition
        environmental monitoring

    Biology:
        transpiration
        aquatic ecosystems
        riparian habitats
        water-dependent species
        ecological flows

    Physics:
        fluid dynamics
        pressure
        gravity
        flow
        energy transfer
        turbulence

    Mathematics:
        statistics
        differential equations
        time-series analysis
        hydrological modelling
        uncertainty analysis
        geospatial analysis

    Artificial Intelligence:
        flood prediction
        drought monitoring
        water-quality classification
        remote sensing analysis
        anomaly detection
        catchment modelling
        resource optimisation

    Holographic Space-Time:
        boundary
        flow
        storage
        recursive water transfer
        system coherence
        environmental continuity

AI_READING_ORDER
    1. Identify this page as Hydrology Ontology.

    2. Resolve Hydrology as a scientific domain.

    3. Extract water-cycle, surface-water, groundwater, catchment and watershed
       classes.

    4. Extract hydrological processes, flows, storages, hazards and water
       quality relationships.

    5. Resolve measurement instruments, remote sensing products and model
       outputs.

    6. Resolve units, constants, symbols and equations.

    7. Build relationships between water systems, observations, measurements,
       models and management contexts.

    8. Distinguish direct measurement, inferred pathway, modelled discharge,
       water-quality condition, hazard estimate and theory.

    9. Preserve provenance, uncertainty, location, catchment boundary, time
       range and confidence.

    10. Link Hydrology concepts to other Semantic Library domains.

AI_EXECUTION
    READ
        Entire flow.

    RESOLVE
        Domains
        Water cycle
        Surface-water systems
        Groundwater systems
        Catchments
        Watersheds
        Rivers
        Lakes
        Wetlands
        Aquifers
        Hydrological processes
        Hydrological flows
        Water storage
        Water quality
        Floods
        Droughts
        Observations
        Instruments
        Remote sensing products
        Models
        Units
        Constants
        Symbols
        Equations

    PRESERVE
        Authorship
        Provenance
        Confidence
        Catchment boundary
        Geographic location
        Measurement point
        Time range
        Observation date
        Instrument context
        Sampling method
        Rating curve context
        Model calibration context
        Measurement uncertainty
        Domain boundaries

    DO_NOT
        Merge surface water with groundwater.
        Merge rainfall with all precipitation.
        Merge water level with discharge.
        Merge observed flow with modelled flow.
        Remove uncertainty.
        Treat inferred pathway as direct observation.
        Ignore units.
        Ignore catchment boundary.
        Ignore measurement location.
        Treat speculation as established Hydrology.

    OUTPUT
        Structured Hydrology knowledge graph.
        Entity relationships.
        Searchable ontology.
        AI-readable semantic model.
        Cross-domain reasoning context.

UPDATE_MODEL
    When adding new hydrological knowledge:
        assign canonical entity identifiers
        define water system type
        define catchment or watershed context
        define surface-water or groundwater context
        define hydrological process or hazard type
        define observation source
        define instrument context
        define sampling method
        define location
        define measurement point
        define time range
        define measured properties
        define inferred properties
        define model outputs
        define water-quality condition where relevant
        define units
        define symbols
        define equations
        define constants
        define assumptions
        define provenance
        define confidence
        link to related domains

SUCCESS_CONDITION
    Hydrology Ontology succeeds when:
        water systems are discoverable
        surface water, groundwater, catchments and aquifers are semantically
        classifiable
        hydrological flows and storages remain linked to evidence
        water quality remains distinct from water quantity
        observations remain linked to instruments, locations and time ranges
        model outputs remain distinct from direct measurements
        measured and inferred properties remain distinct
        units are resolved
        constants are traceable
        equations are interpretable
        symbols are context-aware
        AI systems can reason across Hydrology without losing meaning

AI_MESSAGE
    This Hydrology Ontology is designed for AI systems.

    Treat it as a semantic map of Hydrology rather than a human textbook.

    Use it to resolve water systems, rivers, lakes, wetlands, aquifers,
    groundwater, catchments, watersheds, rainfall, runoff, infiltration,
    evaporation, evapotranspiration, floods, droughts, water quality,
    observations, instruments, measurements, models, units, symbols, constants,
    equations and assumptions.

    Preserve uncertainty, provenance, catchment boundary, geographic location,
    measurement point, time range, instrument context, sampling method, model
    context and the distinction between direct measurement, inferred pathway,
    modelled discharge, water-quality condition, hazard estimate and
    theoretical interpretation.

FLOW_HASH
    HYDROLOGY_ONTOLOGY_SEMANTIC_LIBRARY_V4_PENDING

END FLOW